1. Field of the Invention
This invention relates to deep fat fryers. In one aspect, this invention relates to extending the usage life of cooking oil in deep fat fryers. In one aspect, this invention relates to a method for extending the usage life of cooking oil in deep fat fryers. In one aspect, this invention relates to an apparatus for automatically extending the usage life of cooking oil in deep fat fryers.
2. Description of Related Art
Typically, cooking oil in a deep fat fryer is used until the total amount of foreign particles or compounds in the cooking oil accumulate so as to negatively affect the color of the cooking oil or the taste of the food prepared with the cooking oil. Upon the occurrence of such triggering events, in accordance with conventional practice, the entire vat of cooking oil in the fryer is drained and replaced with fresh cooking oil.
During the normal operation of a deep fat fryer, a certain amount of oil is removed by the products being fried, a process referred to as dragout, and must be replaced with fresh oil in order to maintain the correct volume for cooking. Typically, restaurants add new cooking oil at the end of the day. The addition of fresh cooking oil necessitated by the dragout to the volume of used cooking oil in the fryer effectively, but only marginally, increases the usage life of the cooking oil or extends the amount of time before the cooking oil has to be discarded and replaced with fresh cooking oil. This is because the additional fresh cooking oil is replacing used cooking oil corresponding to the dragout and this additional fresh oil “refreshes” or decreases the average age of the cooking oil.
Deep fat fryers typically use about 30 to 50 pounds of cooking oil during operation. Despite advanced filtering methods and frying practices, the operation of the fryer degrades the oil at a rate where the entire vat has to be thrown away. This results in thousands of pounds of cooking oil being discarded per year at a typical restaurant. By increasing the cooking oil life, a large percentage of the discarded cooking oil could be eliminated, saving both oil costs and disposal costs.
Current deep fat fryers either rely on the operator to manually refill the vat to the marked oil level depth or use a single oil level sensor to continuously top off and maintain the oil level at the height of the single oil level height sensor. While such practices provide a small amount of cooking oil refreshment, such practices do not substantially increase the usage life of the cooking oil.